Glass fiber drawing mechanism with means for accentuating strand discharge



Oct. 5, 1954 J. F. COURTNEY ETAL ,6 GLASS FIBER DRAWING MECHANISM WITHMEANS FOR ACCENTUATING STRAND DISCHARGE Filed May 11, 1951 5Sheets-Sheet 1 Pa be 0 W 5327/7 1 Uct. 5, 1954 J, COURTNEY ET AL2,690,628

GLASS FIBER DRAWING MECHANISM WITH MEANS FOR ACCENTUATING STRANDDISCHARGE Filed May 11, 1951 3 Sheets-Sheet 2 Oct. 5, 1954 Filed May11-, 1951 J. F. COURTNEY ET AL GLASS FIBER DRAWING MECHANISM WITH MEANSFOR ACCENTUATING STRAND DISCHARGE 3 Sheets-Sheet 3 Patented Oct. 5, 1954UNITED STATES PATENT GLAS S FIBER DRAWING MECHANISM- W ITH. MEAN SFORACCENTUATING STRAND DIS-- CHARGE Joseph" F. Courtney; Evanston, and-Adelb'ert 'G.

Radtke, Chicago, 111., assign'orstoInternational: Harvester: Company, acorporation of New.

Jersey Application May-11, 1951, Serial ,No. 225,883

7 Claims;

This invention relates to'a novel apparatus for.

attenuating a thermoplastic material and has specific reference to themanufacture of glassfibers in the making of glass strands and the'like.Elemental glass fibers are characterized by low tensile strength,susceptibility to abrasion and fracture and extreme fragility andbrittleness.

Due to this nature of the material and the-high speed for drawing thematerialinto fiber form, extreme difficulty has beenexperienced-in providing a satisfactory drawing mechanism which will afford a positivegrasp on the strand with? out deformation and provide a sustainedsubstantially even pullon the strand to obtain ap-- proximately uniformcharacteristics with regard to flexibility, diameter, texture, etc.throughout its length.

A generalobject of the invention is to-devisea novel drawing mechanismwhich obtains a gentle grasp on a substantial length of astranol andeifects an approximately uniformpull on the strand without imposing hightransverse stresses thereon.

A further object is to obtainanarrangementwhich provides a grasp on thestrand-by continuously moving opposed endlesssurfaces-moving aboutpredetermined axes in such manneras to utilize the centrifugal forcesthereon tobias the surfaces towards each other and produce a graspingefiect onthe strand;

A more specific object is to provide a drawing device presenting opposedcontinuous surfaces receiving an extensive length of the strand there--between, at least one of these surfaces beingdirectly actuated andatleast' one-of these'sura faces being yieldably urged. against thestrand: by impressing a centrifugal and/or. other force thereagainst.

In several arrangements, a pluralityof opposed belts are employed andarranged toutilize the centrifugal force to grasp the strandandinseveral of these embodiments the grasping action is accentuated bycausing the strand andbeltsto move at their graspingareasalong a curvedor sinuous path.

A more specific further. object is toprovide sucha strand attenuatingdevice withnovel means for accentuating discharge of the strand from thedevice.

These and other objects of the invention will become more apparent fromthe specification-and drawings wherein:

Figure 1 is a side elevational view of one embodiment of the invention.

Figure 2 is a side elevational view of a still.

further embodiment of the invention.

Figures 3to 5 illustrat -another modifications Figure 3 iscomparable toFigures hand- 2; Figure dis a radial'sectionai viewon-the 1ine-5 5 of-'Figure- 3; and Figure 5-.is-a. f1'agmentary edge' view thereof.

Figures 6 and '7 illustrate-a still further em'-- 4 assembly againsta=side of sheave M through=a- V-groove Id therein, the filamentsdischarging from the gathering sheave incompacted' form and'formingthestrand 8 The strand l8- isthen' pulled downwardly and adirection-to-' wards the sheave and then passed through' the' rotatingdrawing" mechanismgenerally indicated" lfi'if, said -mechanismincluding-anendless drive" belt- 02 and an" idler: belt l W4, disposedin a 1 substantially vertical plane;

The drive belt W2 is looped undera pulley which isdriven througha:sha-ftLI98 by-a motor 1 I'Q'L The-supper extremityof the: belt-"istrained over a: pulley I I-2." Similarly, the: idler belt: Isa-11slooped over a pulley: l li 'and -unden" The axes of 'rotatio'rrof allofthese pulleys are substantially: parallel and pref a pulley H erablyhorizont'al; The-belts I02 and lll l 'are" arranged in: the form: ofovals and disposed' witli l i the advance" flights- I I8 and imrespectively alongside each otherand with the outer sur-- faces thereofin J facing relationship for receiving the strand thereb'etween, saidstrand being' guided to the drawingmeans bys a centering'fork 122 orgrooved idlerr guide sheave; rotation-of the pulleys lfi fi and! l iiiare prefer ably fixed'sandrtheaxes ofrotation' I M- and: I25 ofthe.pulleys H2 and; H4: areadjustable- As shown in-Figure-Z a pulley orroller l28bearsx "againstthe backside of flight i IBzand is journaied'las at 132 on a. substantially horizontal axis-(tow the IOWBl'iEIldOf anarmliitw'hichnis pivoted on a preferably fixed horizontalzaxisiSBwintermedi-s ate the ends: thereof.- The arm: lt lz rot'atablysupports at its upper. endon a=substantial1y hori- I zontal axis asatI38 aroller-lflfinvhich isenzgaged w-iththe-backside of. the: advance:flight:

1290f the belt M4.- The rollers I28 land ll-l0 are biasedcontra-directionally? with respect-to the; vertical planepassingtherebetween in'zorder;

The axes: of

to deflect the advance fiights from normally vertical lines to a sinuousor curved path whereby the strand between the advance flights and thegrasping lengths of the belts are caused to move or sinuate along agentle sinuous or curved route. This arrangement permits the applicationof light transverse clasping or grasping pressure against the strandalong an extended length thereof and at the same time affords anefficient frictional engagement between the strand and the belts whichis amplified by the wedging tendency between the belts and strand suchthat sufficient force is applied along a continuous length to providefor effective drawing of the strand. It will be noted that the beltsrotate in the direction of the arrows.

The arm or lever 34 is biased in a direction urging the rollers 128 andI30 against the respective flights by means of a tension spring I40which at one end is hooked as at I22 to the arm I34 intermediate pointsI32 and I35 and at the other end is fixed as at I44 to the right oflever I 34. The pulleys and rollers are disposed far enough apart toadmit a workmans hand between flights [I8 and I25 without inury.

It will be understood that all of the strand which discharges from thedrawing means H prior to the attainment of desired drawing rate ispreferably discarded and that when a strand is of correct dimension, itis passed through the blower 46 as in our companion application forGlass Fiber Drawing Mechanism and Process, Serial No. 221,596, filedApril 18, 1951, said blower being supported immediately below thedischarge of the drawing means and depositing the strand I8 into thecanaster 58. The blower d6 pulls at the strand IS in excess of thedischarge rate of the drawing means but with slipping eifect so as notto break the strand. In addition, the rotation of the belts developscentrifugal forces which tend to throw the advance flights of thesebelts towards each other whereby producing a gentle grasping eifectalong an extensive length of a strand. Static electricity dischargersI39 may be provided.

Referring now to Figure 2 the drawing means generally designated 200comprises an entry zone 202 between the upper ends of advance flights orsections 204 and 206 of belts 208 and 2H) which on their outer oropposed sides are arranged in contact with a vertical length of strandI8 which adjacent to the entry zone is guided by a centering fork 2I2,the lower end of the strand discharging below the belts through thenozzle 45 which is applied to the strand after it attains apredetermined size as in all of the previous embodiments. The belt 263is looped over a pulley 2M and passes under a pulley 2I6. Similarly, thebelt 2I0 is trained over a pulley 2I8 and looped under a pulley 220. Thebelts and pulleys are disposed in a common generally vertical plane. Thepulleys are rotatable on substantially parallel preferably horizontalaxes and the pulleys 2I8 and 220 are preferably vertically offset withrespect to the pulleys 2M and ME and arranged in partially verticaloverlap therewith so as to produce a curved or sinuous path to which thestrand is caused to conform as it travels along the belts. Thisarrangement effects a gentle gripping action on the strand which isaugmented by centrifugal force tending to throw the belts toward eachother at their leading lengths. To make this action more aggressiveespecially at the entry zone both belts are driven through pulleys 222and 224 and connected to pulleys 2M and 2I8 respectively. The pulleys222 and 224 are driven by a belt 226 which is trained on a pulley 228driven by a motor 230, said belt 228 having its upper flight passingover the top of an idler pulley 232 and then continuing around the farside of pulley 222 and continuing into the lower flight 234 of the beltwhich passes over the pulley 224 and then joins around the far side ofpulley 228 with the other end of top flight 23B of the belt.

Referring now to Figures 3 through 5, the strand 3% may be guided withina transaxially diagonal groove 302 in the periphery of a guide wheel 304rotatably mounted as at 306.

The strand is directed downwardly to an entry zone 383 of a drawingmechanism generally designated 310.

The mechanism 310 comprises four intercallated pulleys or wheels 3I2,3M, 3I5 and 3I8. A flat belt 320 is trained around the peripheries ofpulleys BIZ and 3H; and another flat belt 322 is trained about pulleys3M and 3I8. Due to the arrangement of the pulleys, the advance flights324 and 326 of belts 320 and 322 are caused to substantially assume theform of a sinusoidal curve to afford a grasping zone for engaging thestrand 300 entered at one or upstream end of the mechanism between thebelts at the entry zone at the pulleys 3I6 and 3H], and discharging atthe other downstream end at the discharge zone 323 from between thesegments of the belts on pulleys M2 and 3M. It will be observed that thestrand 3651 which may be a composite of several strands is thus sinuatedthrough the drawing means and grasped along an extensive length thereof.The present design, as heretofore stated, utilizes preferably flatbelts. In order to retain these belts on the pulleys 3H5 and 358, theouter peripheries of these pulleys are crowned convexly outwardly,however, the crest of the crown is formed cylindrical about the axis toprovide a width coextensive with the lateral extent of groove 392 in theguide sheave, the groove shifting the strand laterally across the beltsto prevent the development of a single track depression in the belts. Itwill be understood that the axes of rotation of pulleys 3l2 and 3H! arepreferably mounted on tensioned adjustable axes and the pulleys 3M and316 on fixed axes.

The specific feature of this design is to pass the strand through asurface area of substantially maximum curvature and is especiallydesirable for drawing several strands simultaneously which requiresmaximum grasping and pulling eifort.

Each pulley is preferably designed to have a peripheral extent of aboutone foot in length and to be rotated at the peripheral speed ofapproximately 10,000 feet per minute. Thus intense centrifugal force isdeveloped to bias the advance flights of the belts toward each other toaccentuate the grasp on the strand. In addition, the tremendous speed ofthe pulleys tends to discharge the strand tangentially to theperipheries of the segments of the belts trained about pulleys 3 I2 and.3M.

The stripping means in the present embodiment comprises a series ofalternating flat areas or facets 33S and cylindrical segment areas 332on the outer peripheries of pulleys 3I2 and 3M. The arrangement of theseareas develops transverse oscillation of the belts at the discharge zonewhich serve to cast off the strand from the belts. Furthermore, thesharp change of direction of the belts from the projected path of thestrand also disengages the strand therefrom so that the strand maydischarge directly into container 334.

The drawing mechanism may be suitably powered from a motor 336 through abelt and sheave linkage 338 driving sheave 3.

Referring now to the modification in Figures 6 and 7, it will be seenthat the general concept is the same as in the previous embodiments butprovides a more compact arrangement and an intermediate graspingintensity.

The strand 600 is guided by a sheave 402 (similar to sheave 304) toshift or play transversely of the grasping width of belts 404 and 486which are looped at their upper extremities about sheaves 408 and 610respectively, and at their lower portions under sheaves M2 and 414.

It will be noted that all of the sheaves are of the same diameter andthat the upper sheaves are spaced radially and rotate on substantiallycoplanar horizontal axes M6 and H 8. Similarly, the lower sheaves arespaced radially and are rotatable on axes 42c and 422 arranged insubstantial horizontal alignment. The sheave 4|2 extends partiallybetween sheaves 410 and 414 and 403 and M0. The arrangement of thesheaves deflects the advance flights 424 and 426 of the belts to form amodified S-shaped grasping zone which at its downstream end terminatesat the discharge zone 428 of the mechanism.

The drawing assembly may be shielded by a member 439 which may have aslit 432 in alignment with the intake between the upper ends of theadvance flights to guide the strand into the drawing mechanism when theprocess is first begun.

The drawing mechanism may be driven by a motor 434 connected to sheaveM2.

In each of these designs the centrifugal force together with the initialtensioning adjustment grasps the strand, and the strand is drawn on acurved surface over an extensive length thereof. A gentle grasp isachieved together with the requisite frictional development to obtainthe desired pull on the material without deforming the material orfracturing the same.

It will be understood that the guide wheel shown in the latter twoembodiments may be substituted for the centering fork shown in the firstseveral embodiments.

What is claimed is:

1. Apparatus for attenuating strands of material comprising a pair ofbelts having opposing strand-grasping sections transversely deflected toproduce a flowing approximately S-shaped grasping zone terminating in adischarge end, said belts arranged to rotate about axes to developcentrifugal forces biasing the belts towards each other, and dischargeaccentuating means for casting of said strand loose from said belts atsaid discharge end of said grasping zone and comprising a sheaverotatably supporting at least one belt and provided with a non-roundperipheral surface tracking said belt thereabout for oscillating thebelt transversely and guiding the belt to move sharply away from thestrand so as to cast loose therefrom.

2. In an apparatus for drawing glass strand, a pair of flat belt loops,a sheave disposed within each end of each loop and provided with acrowned peripheral surface in contact with the internal surface of theassociated loop, said loops having corresponding lengths disposed inpressing contact with each other along complementary grasping surfacesdefining an intake at one end and a discharge at the other end, andstrand guide means comprising a sheave with a peripheral transaxiallydiagonal groove adapted to receive the strand at said intake andpursuant to rotation thereof to course the strand laterally on saidbelts as said strand is being drawn between said grasping surfaces, allof said sheaves mounted on parallel axes and said groove having alateral traverse less than the Width of said belts.

3. In an apparatus for drawing glass strand a pair of belt loops,rotatable support means disposed within each end of each loop in contactwith the internal side of the associated loop, said loops havingcorresponding lengths disposed in pressing contact with each other alongcomplementary grasping surfaces providing an intake at one end and adischarge at the opposite end, and vibrating means operativelyassociated with at least one of said loops for oscillating the samesharply transversely at said discharge for stripping the strandtherefrom.

4. Apparatus according to claim 3 and said vibrating means comprising anonround face on the rotatable support means associated with said oneloop at said discharge, said rotatable support means movable at asubstantial speed suflicient to obtain a rapid oscillatory effect on thebelt loop.

5. Apparatus according to claim 4 and said nonround face comprising aseries of flats and intervening crowned surfaces continuous betweenadjacent flats disposed about the periphery of said rotatable supportmeans.

6. Apparatus according to claim 5 and driving means directly connectedto said rotatable support means comprising said nonround face toaccentuate oscillation thereby of the related belt loop.

7. A glass fiber drawing apparatus comprising two flat belt loops eachpassing about a wheel at each end, said loops engaging each other at adetermined region and having an intake at one end and a discharge at theother, said wheels rotatable on generally horizontal axes, each wheelcomprising a cylindrical periphery crowned at its axial extremes toretain the belt thereon, and only noncylindrical spots on thecylindrical periphery of the wheels at said discharge of said region.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 109,430 Leavitt Nov. 22, 1870 461,855 Thompson Oct. 2'7, 18911,092,631 C'asablancas Apr. 7, 1914 1,443,514 Williams Jan. 30, 19232,067,251 Taylor Jan. 12, 1937 2,239,863 Schlipp Apr. 29, 1941 2,335,135Staelin Nov. 23, 1943 2,348,182 Slayter May 2, 1944 2,418,873 Fletcheret a1 Apr. 15, 1947 2,448,499 Swann Aug. 31, 1948 2,497,511 Neisler, Jr.Feb. 14, 1950 FOREIGN PATENTS Number Country Date 16,297 Great Britain1898 22,127 Great Britain 1892 525,283 Great Britain Aug. 26, 1940

